JPH0640654B2 - Call amplification device - Google Patents

Description

DETAILED DESCRIPTION [Overview] A direct connection to a telephone line to amplify a call signal between telephone terminals. Even if the line loss is large or a long-distance line is connected, it is clear. If you can make a phone call and the line loss is small or if you are connected by a short distance line,
The call signal is transmitted by bypassing the amplifier.

[Industrial application field]

The present invention relates to a call amplifying device that amplifies a call signal between telephone terminals.

In the case where the length of the subscriber line between the exchange and the telephone terminal is long, etc., even if the line loss is within the regulation, if the line loss is close to the limit, clear communication becomes difficult. In such a case, it is desired to amplify a call signal with a simple configuration to enable clear call.

[Conventional technology]

In the case of a long-distance call, etc., when the call signal level decreases due to line loss, conventionally, a means has been adopted to select the winding ratio of the relay loop wheel to compensate for the drop in the call signal level. It was Further, in a telephone terminal for a hearing-impaired person or the like, a configuration has been adopted in which only a received signal is amplified by an amplifier and added to a receiver, or an amplified output is added to a speaker to perform a call in a freehand state. Further, in a telephone terminal using a ceramic handset, an amplifier is connected to each of the ceramic handset and the ceramic handset, and these amplifiers are set to a predetermined gain in advance, and impedance matching to the line is made. Has been taken, and howling may occur when the gain is increased.

If an amplifier is directly connected to the telephone line to amplify the call signal, it is necessary to amplify the call signal in both directions and to transmit the DC loop signal, dial pulse signal, ring signal, etc. as they are. Therefore, even an amplifier that simply amplifies a bidirectional call signal via a hybrid circuit cannot be directly connected to a telephone line.

[Problems to be solved by the invention]

As described above, in a telephone terminal in which the line loss is close to the specified value limit, the line loss may exceed the specified value due to aging or the like. Also, when the call transfer subscriber's telephone terminal returns to connect to the transfer destination, as in the transfer telephone method, the line between the calling subscriber and the transfer destination subscriber becomes very long, resulting in a large line loss. There is. In such a case, it becomes necessary to amplify the telephone signal because the telephone call signal level decreases and the telephone conversation becomes unclear.

However, connecting the amplifier directly to the telephone line
Since it is necessary to directly transmit the DC loop signal, dial pulse signal, ringing signal, etc., it is difficult. To solve this problem, it is conceivable to relay these signals by a relay or the like. However, in that case, there is a disadvantage that the configuration is complicated including a drive circuit such as a relay.

It is an object of the present invention to directly connect to a telephone line and enable bidirectional amplification of a call signal with a simple configuration.

[Means for solving problems]

The speech amplification apparatus of the present invention is provided with an AC amplifier for amplifying a transmission signal and a reception signal, respectively, and a circuit for passing a DC component such as a DC loop signal in parallel, and is referred to FIG. explain.

A hybrid circuit (6, 7) for separating / mixing a transmission signal and a reception signal of a call signal, and a capacitor connected to the hybrid circuit (6, 7) so as to pass only an AC component and block a DC component. (8, 9), AC amplifiers (1, 2) for respectively amplifying the transmission signal and the reception signal separated by the hybrid circuit (6, 7), the hybrid circuit (6, 7) and the capacitor (8). , 9) and an AC amplifier (1, 2) are connected in parallel with the circuit,
A circuit (3) having an inductance for blocking an AC component and passing only a DC component, the circuit (3), a capacitor (8, 9), a hybrid circuit (6, 7), and an AC amplifier (1, 2). And a bypass circuit (5) that bypasses this circuit, and a switching circuit (4) that switches by a control signal from the outside. The switching circuit 4 is operated by a signal from the terminal S1. 1 shows a case in which the relay circuit 10 comprises a contact operated by the relay 10. When the switching circuit 4 is in the illustrated state, the AC amplifiers 1 and 2 amplify the transmission signal and the reception signal.

[Action]

When the switching circuit 4 is in the illustrated state, the call signal transmitted from the telephone terminal of the other party via the telephone line is added to the AC amplifier 1 via the switching circuit 4, the capacitor 8 and the hybrid circuit 6 to be amplified, so that the hybrid It is added to the telephone terminal via the circuit 7, the capacitor 9 and the switching circuit 4.

A call signal from the telephone terminal is added to the AC amplifier 2 via the switching circuit 4, the capacitor 9 and the hybrid circuit 7 to be amplified, and sent to the telephone circuit via the hybrid circuit 6, the capacitor 8 and the switching circuit 4. .

DC components such as a DC loop signal, a dial pulse signal, and a ringing signal are blocked by the capacitors 8 and 9 and transmitted as they are through the circuit 3 including an inductance. Therefore, bidirectional call signals are amplified and transmitted,
The DC component is transmitted as it is.

When the switching circuit 4 is switched in the opposite manner to that shown in the figure, the telephone line and the telephone terminal are connected via the bypass circuit 5, so that the call signal is transmitted as it is without being amplified.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention.
2 AC amplifier, the choke coil 13 constituting the circuit for passing a DC _component, 14 1-14 ₄ switching contacts constituting the switch circuit, 15 is a bypass circuit, 16 and 17 hybrid transformer, the 18,19 DC blocking capacitors, 20 and 21 are balance networks, 22 is a relay that operates switching contacts, 23 is a transistor, 24
Is an inverter and 25 is a switch.

AC amplifiers 11 and 12 are hybrid transformers 16,
The choke coil 13 is connected in parallel via 17, and the choke coil 13 and the choke coil 13 are connected in parallel.

When the switch 25 is in the illustrated state, the output signal of the inverter 24 is at a low level, the transistor 23 is in an off state, and no current flows through the relay 22, so that the contacts 14 _{1 to} 14 ₄ thereof are in the illustrated state and the bypasses are bypassed. The telephone line and the telephone terminal are connected via the circuit 15, and the call signal is transmitted without being amplified.

When the switch 25 is turned on, the output signal of the inverter 24 becomes high level, the transistor 23 is turned on, and a current flows through the relay 22 due to the voltage of + V. Therefore, the contacts 14 _{1 to} 14 ₄ thereof are switched and connected. The telephone line and the telephone terminal are connected via the AC amplifiers 11 and 12. Since the DC components such as the DC loop signal, dial pulse signal, and ringing signal flow through the choke coil 13, they are transmitted as they are, and the bidirectional call signals are amplified and output.

If the switch 25 is provided in the telephone terminal and the switch 25 is turned on when the call signal level is low, the call signal is amplified. Therefore, clear call is possible even when the line loss is large.

FIG. 3 is an explanatory view of an embodiment applied to a home device of the present invention, 31 is an amplifier device including a circuit for amplifying a bidirectional call signal and a circuit for passing only a DC component, and 32 is a switching device. Switching contacts forming a circuit, 33 is a bypass circuit, 34 is a home main unit, 35 is a telephone terminal, 3
Reference numeral 6 is a relay for operating the switching contact, 37 is a transistor, and 38 is an inverter.

The in-home main device 34 is connected to the telephone terminal 35 by a call line and a signal line. When the relay 36 is not operating, the switching contact 32 is in the illustrated state, and the home main unit 34 is connected to the telephone line via the bypass circuit 33.
In this in-home main unit 34, when the response of the partner telephone terminal is detected at the time of calling from the telephone terminal 35, or when the response of the telephone terminal 35 is detected at the time of incoming, a control signal of "0" is sent to the inverter 38. Add. Thereby, the transistor 37 is turned on, the relay 36 operates, and the switching contact 32 is switched and connected to the amplifying device 31 side. Therefore,
When in a call state, the amplifier 31 is automatically connected to amplify the call signal.

FIG. 4 is an explanatory diagram of an embodiment applied to the exchange of the present invention, in which MM is a main memory, MPU is a master processor,
RAM is random access memory, MB is main bus,
SB is a sub-bus, SG and MG are gate circuits, INV is an inverter, CL is a clock signal input terminal, and SPU1 to SPU.
PUn, SPU11 to SPU1p are sub-processors, S
PC is a channel controller, NW is a channel network, LC11-L
Cnm is a subscriber circuit, TRK11 to TRDpm are various trunks, and AMP is an amplifier.

The amplifier AMP includes an AC amplifier that amplifies a bidirectional call signal and a circuit that talks a DC component.
The case where the telephone line is connected via the trunk TRK11 is shown. Further, the clock signal of "1" from the clock signal input terminal CL is added to the master processor MPU as an interrupt signal and is also added to the gate circuit MG, so that the master processor MPU operates as a sub processor SPU.
Control data for 1 to SPUn and SPU11 to SPU1p are written in the area corresponding to the sub processor of the random access memory RAM via the main bus MB and the gate circuit MG, and the sub processors SPU1 to SPUn, SP
The control data written in each corresponding area is read from U11 to SPU1p.

Next, when the clock signal becomes "0", the inverter INV
Since it is inverted by "1" to become "1", the gate circuit SG is opened and becomes an interrupt signal to the first sub-processor SPU1.
B, random access memory R via gate circuit SG
The control data written in the AM for the self is read to control the subscriber circuits LC11 to LC1m, and the subscriber circuit L
The subscriber status information detected by C11 to LC1m is written in the random access memory RAM, and the next sub processor S
Transfer the interrupt signal to PU2.

Each of the sub-processors performs the above-mentioned operation according to the interrupt signal which is sequentially added.
PU1 to SPUn and SPU11 to SPU1p are "0"
Random access memory RA within the period of the clock signal of
M will be accessed to read and write data to and from the master processor MPU. Then, the master processor MPU uses the subscriber circuits LC11 to LC1m.
Also, it recognizes the states of the trunks TRK11 to TRKpm and adds control data to the speech path control device SPC, and controls the speech path network NW by this speech path control device SPC.

For example, when a subscriber accommodated through the subscriber circuit LC1m makes a call to a subscriber connected to a telephone line with a large line loss, the sub-processor SPU1 includes the call-out information including the accommodation position information. Is written in the random access memory RAM, and the master processor MPU reads it to perform control according to the call processing procedure.

Then, by performing processing such as dial reception, analysis, and outgoing route setting, the trunk TRK11 is captured, and the calling telephone terminal is called. In this case, in the amplifier AMP, the AC amplifier is bypassed by the bypass circuit 15 (see FIG. 2). Trunk TRK1 that the other party's telephone terminal responded
1, master processor MPU via sub-processor SPU11, sub-bus SB, gate circuit SG, random access memory RAM, gate circuit MG, main bus MB
When it is identified, the communication path network NW is controlled through the communication path control device SPC to set the path of the dotted line, and the bypass circuit 15 of the amplification device AMP is disconnected. As a result, the call signal is amplified and a clear call is made.

More amplifiers AMP can be provided,
In addition, the amplifier AMP is directly accommodated in the communication network NW,
When connecting to a telephone line with a large line loss, it is possible to connect the telephone terminals via the amplifier AMP under the control of the communication network NW.

〔The invention's effect〕

As described above, according to the present invention, since the transmission signal and the reception signal are respectively amplified by the AC amplifiers (1, 2) connected between the hybrid circuits (6, 7),
Even if you are connected via a telephone line with a lot of line loss,
A clear call can be enabled.

Further, by connecting the circuit (3) that passes only the DC component such as the inductance in parallel to the hybrid circuit (6, 7) and the AC amplifier (1, 2), the DC component such as the dial pulse can be obtained. Since the signal can be passed, the call signal can be amplified by the AC amplifiers (1, 2), and the dial pulse or the like can be talked without passing through the AC amplifiers (1, 2). Therefore, there is an advantage that it is possible to directly connect to the telephone line.

Further, when the switching circuit (4) controlled by the external control signal is switched and connected to the bypass circuit (5) to bypass the AC amplifiers (1, 2) and the like, it is not necessary to amplify the call signal. Therefore, there is an advantage that the switching circuit 4 can be applied to both a telephone line that needs to amplify a call signal and a telephone line that does not need to amplify.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of an embodiment applied to a home device of the present invention, and FIG. 4 is an exchange of the present invention. It is explanatory drawing of the Example applied to. (1, 2, 11, 12) is an AC amplifier, (3) is a circuit such as an inductance, (4) is a switching circuit, (5, 15) is a bypass circuit, (6, 7) is a hybrid circuit, (8,
9) is a capacitor, (10) is a relay, (13) is a choke coil, (14 _{1 to} 14 ₄ ) are switching contacts, (16,
17) is a hybrid transformer, (18, 19) is a capacitor, (20, 21) is a balance network,
(22) is a relay, (23) is a transistor, (24)
Is an inverter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Koike 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Inventor Noriya Sugimoto 2-18-2 Nishigotanda, Shinagawa-ku, Tokyo Company Hasegawa Electric Co., Ltd. (56) References JP-A-48-66705 (JP, A) JP-B-52-11167 (JP, B1)

Claims (1)

[Claims] 1. A call amplifying device which is connected between a telephone line and a telephone terminal and amplifies a call signal. A hybrid circuit (6, 7) for separating and mixing a call transmission signal and a reception signal. ), A capacitor (8, 9) connected to the hybrid circuit (6, 7) so as to pass only the AC component and block the DC component, and the transmission circuit separated by the hybrid circuit (6, 7). An AC amplifier (1, 2) for amplifying a speech signal and a reception signal, respectively, and a circuit including the hybrid circuit (6, 7), the capacitors (8, 9) and the AC amplifier (1, 2) in parallel. A circuit (3) having an inductance for blocking an AC component and passing only a DC component, the circuit (3), the capacitor (8, 9), the hybrid circuit (6, 7), and AC amplification (1,2) and a circuit including a bypass circuit for bypassing the said circuit (5)
And a switch circuit (4) for switching between and by a control signal from the outside.